1. Field of the Invention
The present invention relates to a rider restraint apparatus. In particular, the present invention relates to a rider restraint apparatus, which is suitable for a small vehicle and is capable of allowing a rider to leave the vehicle freely when there is no need to restrain the rider on the vehicle.
2. Description of Background Art
A rider restraint apparatus of a small vehicle has been hitherto known in the background art. The rider restraint apparatus according to the background art includes an airbag that absorbs impact which the rider is subjected to when the vehicle crashes and a seat belt that prevents the rider from leaving forward to enhance the effect of the airbag to absorb impact. In four-wheel passenger vehicles and the like, to obtain sufficient impact absorption by an expanded and inflated airbag, it is necessary to use a seat belt configured to be strained upon detection of impact together with the airbag. In small vehicles such as two-wheeled vehicles, the use of a seat belt unit is considered to further enhance the effect of the airbag. Moreover, in small vehicles such as two-wheeled vehicles, it is desirable that the restraint by the seat belt be released when a secondary motion occurs after a collision.
To solve the aforementioned problems, Japanese Patent Laid-open Publication No. 2003-276668 discloses a technology that restrains the rider with a seat belt to further enhance the impact absorption effect of the airbag and releases the restraint at a predetermined period of time after the airbag, working with a collision detection sensor, starts inflating and expanding or when a fall sensor detects secondary motion after a collision.